In an internal combustion engine, major aspects of modern engine control require knowledge of the engine position within the 720 degree crankshaft rotation that makes up the four-stroke cycle, e.g. individual cylinder control, spark, or knock control. Therefore, it is important to identify the phase of an internal combustion engine. Identifying phase is also important for the enhanced performance of and improved emissions from internal combustion engines. To achieve this, synchronization is required in fuel injectors in diesel engines. Synchronization is also required in spark plugs in petrol engines. This synchronization of diesel or petrol engines requires information of the current phase of cylinders in internal combustion engines.
In a known method, a pair of sensors is employed to identify the phase of an internal combustion engine. A crank sensor and a cam sensor are mounted on the crankshaft and the camshaft, respectively. The crank sensor determines the crank angle with respect to the top dead center of a cylinder in the internal combustion engine. The cam sensor differentiates between the intake and power strokes of the internal combustion engine. The combination of the crank sensor and cam sensor identifies the phase of the internal combustion engine. However, installing two sensors adds cost and complexity to the internal combustion engine assembly.
In another known method, a single cam sensor is mounted on the camshaft, which can determine both crank angle and phase of the internal combustion engine. Since a camshaft rotates at half the speed of the crankshaft, the cam sensor can differentiate between the intake and power stroke of an internal combustion engine and identify the phase of the internal combustion engine. However, the single cam sensor is expensive and less accurate.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.